Illumination sources, also referred to as illuminates herein, are not typically pure white, but instead have a bias towards a particular color. The color bias is usually measured in terms of a color temperature. The human eye compensates for illumination that is not pure white, so that colors appear relatively consistent over a wide range of lighting conditions. However, electronic sensors that are used to capture images are unable to compensate for differing lighting conditions having different color temperatures.
A typical sensor used in an electronic image capture device, such as a digital camera or digital video camera, will capture an image that exhibits a color shift attributable to illumination from a non-pure white source. The color shift exhibited in the captured image appears unnatural to the human eye and contributes to a perception that the sensor or capture device is of low quality and unable to accurately capture real world images.
The captured image can be processed to compensate for the lighting conditions and color temperature of the illuminant. However, because the white balance compensation depends on the color temperature of the illuminant, the application of a white balance compensation configured for an illuminant at a first color temperature typically does not correct for the color temperature of a second illuminant, and may further degrade the image quality by introducing additional color shift into the image.